It’s just that once the VM has been moved to the new cluster,
selecting console results in the same behavior, but that virt-viewer
starts and stops within a second.
In order to debug, you will need to compare the files provided when you
press the "console" button from both clusters and identify the problem.
Have you compared the firewalld ports on 2 nodes (old and new cluster)
?
Best Regards,
Strahil Nikolov